It is known to use magnetoresistive sensors as proximity sensors, motion sensors or position sensors. In the sensors, an external magnetic field is utilized, which produces a proportional voltage signal of the sensor element when the position of the object to be detected changes relative to the source of the external magnetic field. Such magnetoresistive sensors are used, for example, for detecting reference marks in crankshaft angle measurements.
The sensor elements measuring the magnetic field do not usually operate in their saturation range and are based on the principle of the anisotropic magnetoresistive effect. It is therefore known to superimpose on these sensor elements a magnetic field stabilizing the transfer characteristic, which magnetic field is usually produced by a supporting magnet assigned to the sensor element. In the case of passive, ferromagnetic objects to be detected, the magnet is further used for the purpose of providing an operating field whose change is detected under the influence of the object. The magnet and the sensor element are then in a defined fixed position relative to each other. It is known that already slight positioning tolerances between the sensor element and the magnet in the sensitive direction lead to an offset of the characteristic curve of the sensor element. This characteristic curve offset must be compensated by subsequent trimming of the magnetoresistive sensor.